Before this fix, a reverse asset exchange after a forward asset exchange process will report an index error because the confirm function is called after redeem but is not after init.

update fabric from 1.4.6 to 2.0.1

broker chaincode need to rollback according to a unique id instead of params passed from outside.

1. remove some unused code
2. add .golangci.yml for linter rule
3. add make prepare command